Coffee Grinder

ABSTRACT

A tamping augur may be controlled in various ways to obtain a consistent fill height and uniformity in the distribution of coffee grinds in a portafilter.

FIELD OF THE INVENTION

The invention relates to coffee grinders and more particularly toconical burr grinders. More specifically, the invention addressesimprovements to a tamping augur that may be associated with a coffeegrinder.

BACKGROUND OF THE INVENTION

Conical burr coffee grinders are well known. It is possible for aconical burr grinder to require cleaning or maintenance to remove grindblockages. In order to disassemble a conical burr grinder for thesepurposes, typically the lower burr assembly including the conical shapedlower burr is removed from the grinder. In many instances, the lowerburr assembly is secured by a nut. When the nut is removed, the lowerburr and the related components in the assembly are removedindividually. However, it can be difficult for a user to remove some ofthe small components associated with the lower burr assembly in thesmall and partially enclosed area of the grind chamber. Further, theuser may be unfamiliar with a particular order of re-assembly, each ofthe components. In some instances, user will employ a vacuum cleaner toremove debris from the grind chamber. If the user has not removed all ofthe components, these may inadvertently be drawn into the vacuumcleaner. In some instances, the nut that secures the lower burr assemblyis reverse threaded or may need a specific tool that can fit within therestricted space of the grind chamber.

A tamping augur comprises a rotating augur fan that fits within orotherwise cooperates with the filter basket of a portafilter. The augurfan of the tamping augur rotates within the filter basket to bothcompress the ground coffee in the filter basket and create a uniformupper surface. However, it is practically inevitable that there will bea clearance between the outer periphery of the augur fan and the innerwall of the filter basket. It is undesirable to have ground coffeeattached to the inner wall of the filter basket above the level of thecompacted grinds.

It is known to combine an espresso making machine with an integralcoffee grinder. However, the tamping of the grinds into the portafilterrequires skill. Users that do not possess this skill would benefit froma motorised tamping augur integrated with the coffee grinder. It wouldbe additionally convenient to allow the grinder and augur to be operatedby the action of the portafilter without resort to other user controlssuch as push buttons.

Boilers in an espresso coffee maker such as a steam generating boilerand a boiler for heating water for coffee accumulate scale during use.The extent of the scale depends on the hardness of the water being used.The accumulating scale degrades the performance and longevity of theboilers.

It is known to incorporate a conical burr grinder in an espressomachine. A conical burr grinder has an upper burr and a generallyconically lower burr that forms a portion of a lower burr assembly. Whenthe coffee grinder is dirty, obstructed or jammed, it may be necessaryto remove the lower burr assembly from the grinder. This is oftencomplicated, inconvenient or requiring special tools.

The performance of a motorised tamping augur can also be potentiallyimproved by incorporating a height adjustment mechanism for the augurfan. In this way, inconsistencies in manufacturing and user preferencesregarding the compaction height of a dose and portafilter may be useradjusted, as required.

Some tamping augurs also provide for less than uniform distribution andcompaction of the grounds below augur fan, within the portafilter.Irregularities in the distribution of coffee grinds result in a lessthan optimal brew because water flowing through the portafilter willtend to bypass more compacted areas in favour of less compacted areas.

In an automated or semi-automated machine, methods and apparatus arealso required for determining when a pre-established fill height orlevel of compaction has been reached with respect to the grinds in aportafilter.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the technology to provide a conical burr grinderhaving a lower burr assembly that can be removed easily and intact

It is another object of the technology to provide a lower burr assemblythat is not retained by a nut or other fastener.

It is another object of the technology to provide an augur fan havingone or more peripheral wipers.

It is yet another object of the technology to provide a coffee grinderhaving a lower burr assembly that is easy to remove.

It is a further object of the technology to provide a convenient way ofde-scaling the boilers found in an espresso machine.

It is an additional object of the technology to provide a way ofcontrolling a coffee grinder and tamping augur in an espresso machineusing the interaction between a portafilter and a device that supportsit during filling and tamping.

It is a further object of the technology to provide a tamping augur fanheight adjustment mechanism.

It is yet a further object of the technology to provide an augur fanthat pivots to an off-axis orientation initially and reverts to anorientation that is perpendicular to the rotation axis as the tampingload increases.

It is also an object of the technology to provide a motorised tampingaugur with a height adjustable augur fan.

It is also another object of the technology to provide a coupling andspacer arrangement that may be interposed between a drive shaft and anaugur fan.

It is also an object of the technology to provide a tamping augurassembly that reverses its direction of rotation in order to obtainuniformity in the distribution of coffee grinds within a portafilter.

It is also an additional object of the technology to provide a coffeemachine or tamping augur assembly that is microprocessor controlled, themicroprocessor obtaining a current or load signal from a tamper augur'smotor and comparing it to a pre-established threshold that isassociated, directly or indirectly with the microprocessor ceasing theoperation of the device's coffee grinder or tamper.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

In order that the technology be better understood, reference is now madeto the following drawing figures in which:

FIG. 1 is a perspective view of an augur fan with wiping blades.

FIG. 2 is a top plan elevation of the augur fan depicted in FIG. 1.

FIG. 3 is a sectional view of a tamping augur fan within a filter basketof a portafilter as seen through line B-B of FIG. 2.

FIG. 4 is an exploded perspective view of an augur fan and its wiperblade inserts.

FIG. 5 is a cross sectional view of a coffee grinder incorporated intoan espresso making machine.

FIG. 6 is an exploded perspective view of a lower burr assemblyillustrating three different shaft variations.

FIG. 7 is a cross sectional view of a lower burr assembly incorporatinga bayonet attachment feature.

FIG. 8 is a cross sectional view of a lower burr assembly utilising athreaded interconnection between the lower burr shaft and its drivingshaft.

FIG. 9 is a cross sectional view of a lower burr assembly illustrating amagnet in the lower burr shaft.

FIG. 10 is a cross sectional view of an upper burr assembly and bail.

FIG. 11 is an exploded perspective view of the upper burr assembly shownin FIG. 10.

FIG. 12 is a schematic diagram illustrating an espresso making machinehaving internal boilers for both steam and water.

FIG. 13 is a perspective view illustrating the boilers in an espressomaking machine, their drain valves and the removable drip tray.

FIG. 14 is a perspective view of an espresso making machineincorporating an integral grinder and tamping augur, also illustratinguser accessible drain valves.

FIG. 15 illustrates the insert, home and start/stop positions of aportafilter with respect to a fill head that supports it.

FIG. 16 is a perspective view of a portafilter and a mechanism foractivating the grinding motor and tamping augur.

FIG. 17 is a perspective view of a portafilter and a mechanism foractivating the grinding motor and tamping augur.

FIG. 18 is a perspective view of a portafilter and a mechanism foractivating the grinding motor and tamping augur.

FIG. 19 is an exploded perspective view of an assembly for retaining aportafilter during the filling and tamping operations disclosed in thespecification.

FIG. 20 is a plan view of a fill head and portafilter.

FIG. 21 is a perspective view of a motorised tamping augur with heightadjustment mechanism.

FIG. 22 is a perspective view of a tamping augur height adjustmentmechanism.

FIG. 23 is an exploded perspective view of a tamping augur fan withoff-axis functionality.

FIG. 24 is a side elevation, cross sectioned to illustrate the augur fandepicted in FIG. 23.

FIG. 25 is a side elevation, cross sectioned to illustrate the augur fandepicted in FIG. 23.

FIG. 26 is a perspective view of the augur fan shown in FIGS. 23-25.

FIG. 27 is a schematic diagram of an espresso making machine having ahopper, grinder and augur.

FIG. 28 is a flow charge illustrating a way to operate a tamper in twodifferent directions to achieve uniformity in the distribution of grindsin a portafilter.

FIG. 29 is a flow chart indicating a device and method for determiningthe proper filling of a portafilter by monitoring the current draw ofthe tamper augur's motor and comparing it to a pre-establishedthreshold.

BEST MODE AND OTHER EMBODIMENTS

As shown in FIG. 1, the fan 10 of a tamping augur comprises a hub 11from which radiates one or more tamping blades 12. In this example,there are two blades. Each blade is approximately semi-circular in planview as shown in FIG. 2. The each blade has an approximately helicalconfiguration, having a leading edge 13 higher in elevation than atrailing edge 14. There is a preferably parallel gap passage or othergap 15 between the blades that allow coffee grounds to fall between themfrom above. When the augur fan is rotated 16 the trailing edge 14 actsto compress the grounds beneath it and to smooth the surface of thetamped or compacted grounds below the fan.

As illustrated in FIG. 2, there is a small gap 20 located between theouter periphery of the fan and the inside wall of the filter basket 21.The gap 20 can be effectively closed or reduced with the provision ofwipers or wiper inserts 22 that are retained by the one or more blades,but not necessarily by each blade. In this example, each of the twoblades carries a wiper insert 22. In preferred embodiments, the augurfan body is manufactured from a rigid polymer or a metal and the wiperinserts 22 are elastomeric.

As suggested by FIGS. 1-3, each wiper insert 22 comprises a flat bodyhaving parallel sides 23. The body has, at one end, an enlarged head 24.The other end of the body features a vertically aligned rib, lip or bead25. The lip 25 projects beyond the outer periphery of the augur fan bodyand extends so as to sweep or contact the inner wall of the filterbasket 21. When the augur fan is rotated, the lip 25 acts to clear orwipe debris off of the inner wall of the filter basket.

In this example, the hub 11 has a central tapered bore 17. The centraltapered bore 17 has one or more flat sides 18 for retaining the taperedlower end of the shaft that drives the augur fan. As shown in FIG. 3 thecentral tapered bore 17 may have a recess or pocket 31 at its lower endfor receiving a magnet 32 that may be used to retain the augur fan 10onto the augur fan's steel drive shaft.

A shown in FIG. 4, one way for the body of the augur fan 40 to retainthe wiper inserts 41 is by providing an open ended recess 42 on the rimor outer edge of a blade that is adapted to receive the insert 41. Inthis example, the thickness of the insert 41 is approximately the samethickness as the augur fan blade in the area 43 surrounding the recess42. Each recess comprises a terminal pocket 44 for receiving theenlarged head 45 of the insert. The recess 42 has parallel sides 46 forsnugly receiving the parallel sides of the body of the insert. Aninternal, peripheral rib 47 within the recess cooperates with acorresponding peripheral slot 48 on the insert. Thus, the elastomericinsert 41 can be pushed into the recess and will be retained bycompressive forces, friction and interference between the enlarged head45 and the narrower gap formed between the parallel side walls 42 of therecess.

As shown in FIG. 5, a conical burr grinder 50 includes a motorised driveshaft 51 engages with and rotates an upper burr assembly 52. In thisexample, the upper burr assembly includes a metallic impeller platehaving an array of fins 53, an optional polymeric impeller support 54, aburr shaft 55 a lower burr 56, a washer 57 and a retainer or a circlip58. In the example of FIG. 5, the lower burr assembly 52 is retained onthe drive shaft 51 by a threaded interconnection between the drive shaft51 and the internally threaded bore of the burr shaft 55. Other means ofinterconnecting the drive shaft 51 and the burr assembly 52 will bediscussed below.

A felt washer or other seal 59 may be interposed between the impellersupport and adjacent static parts of the grinder to prevent theinfiltration of particulate matter into the area of the drive shaft 51.

As shown in FIG. 6, an impeller plate 60 has, in this example, a flatcircular hub 61 from which radiates an array of protective blades orfins 62. Each blade or fin 62 has a horizontal portion 63 and avertically extending portion 64. The hub 61 has a central opening 65preferably provided with one or more flat sides so that the impellerblade may be driven or rotated by its burr shaft 66. Torque istransmitted from the impeller plate to the lower burr 56 by one or morelock pins 67. In this example, each locked pin 67 includes a peripheralflange 68 that facilitates trapping the lock pin 67 between the impellerplate 60 and the impeller support 69. The impeller support 69 may haveopenings 70 for receiving the lower end 71 of the lock pin, the openings70 being rebated to receive the flange 68. Thus, the lock pins 67project through openings 72 in the impeller plate 60 and in tocooperating openings (not shown) on the lower surface of the lower burr56. The impeller plate 61 and impeller support 69 may be additionallyfastened together with rivets 73 that pass from beneath the impellersupport, through openings in the impeller support 74, continuing throughopenings 75 in the impeller plate. After insertion, the heads of therivet 73 may be deformed into the rebated openings 75 on the uppersurface of the hub 61.

The polymeric impeller support has a central through opening 76 forreceiving the burr shaft 66. The impeller support also has thickintegral blades or fins around its periphery. In this example, eachblade or fin 77 has a concave front face 78. When the lower burrassembly rotates, the blades or fins 77 act to propel ground coffee outof the grind chamber. When assembled, the metallic fins or blades 62covers, protects or of the impeller plate 60 overlie and protect thepolymeric fins 69 on the impeller support. Accordingly, it is preferredthat the outer most tip 80 of each metallic fin or blade 62 overlaps theouter tip 81 of each polymeric blade 77. This reduces wear on theimpeller support, particularly in the area of the blade tips 81.

FIG. 6 also illustrates three different types of lower burr assemblyshaft 66. A bayonet shaft 82 includes a component of a bayonet fastening83 at a lower end. In this example, the bayonet fastening is the femalecomponent of a bayonet fastening. The lower part of the bayonet shaft 82includes a pair of flat sides 84 that are intended to engage and drivethe flat sides of the central bore 65 in the impeller plate 60. Thebayonet shaft 82 also has a circumferential groove 85 for accommodatingthe circlip 58 that retains the lower burr 56. A projection 82 above thegroove 85 act as a finger grip. Accordingly, the sub-assembly comprisingthe impeller support, impeller plate, lower burr and washer are trappedbetween the circlip 58 and a shoulder 86 located on a lower end of theburr shaft 66.

As shown in FIG. 7, the bayonet feature 83 at the lower end of thebayonet style burr shaft engages one or more radially extendingretention pins 90 that extend away from the upper portion of the driveshaft 51. The shoulder 86 of the burr shaft can be seen abutting thelower surface of the impeller plate 60. Thus, the entire lower burrassembly 52 can be inserted, then disengaged from the drive shaft 51 byrotating the bayonet features 83, 90 into and out of engagement. Theupper end of the burr shaft may be slotted 91 so as to admit a screwdriver or other tool for causing the rotation required to engage anddisengage the bayonet features 83, 90.

As suggested by FIGS. 6 and 8, the burr shaft 66, 90 may have a centralblind bore 91, the upper extent of which is threaded 92 to receivecooperating threads 93 formed on an upper extent of the drive shaft 51.

As suggested by FIGS. 6 and 9, the lower burr assembly 52 may beretained on the burr shaft by magnetic attraction between the two. Asshown in FIG. 9, the central blind bore 100 of the burr shaft mayinclude a terminal pocket 101 for receiving a permanent magnet 102. Thelower end of the magnet 102 is in close proximity to the upper end 103of the drive shaft 51. Magnetic attraction thus prevents inadvertentlifting off of the burr assembly 52 from the drive shaft 51. As witheach of the aforementioned examples, the burr shaft 66 includes andupper portion 104 that extends above the circlip 58 and the groove 85that retains it. This extension 104 allows the user to grasp the burrassembly 52 and remove it from the drive shaft 51. The lower end of themagnetic style burr shaft 105, in this example, forms a saddle orchannel 106 that is adapted to receive a one or more driving projections107 formed on the draft shaft 51. In this way, torque is transmittedfrom the drive shaft 51 to the lower burr assembly shaft 105 through theprojection 107 and saddle 106.

FIG. 10 illustrates the upper burr assembly, previously seen in FIG. 5.The upper burr assembly comprises the upper burr 110 and inner portionof the upper burr holder 111 and an outer portion of the upper burrholder 112. As suggested by FIG. 11, the outer portion 112 has externalfeatures such as bayonet features 120 that allow the outer portion toengage the upper burr carriage that retains it. The upper portion alsohave internal threads 121 that cooperate with external threads 122formed around the sidewalls of the inner portion of the upper burrholder 111. The cooperating threads 121, 122 allow for rotationaldisplacement of the inner portion relative to the outer portion.

The outer portion 112 carries a folding handle 123. In this example, thehandle has opposing hands, each featuring an inwardly directed tip 124.The tips 124 are long enough to pass through a pair of openings 125located opposite one another and near the upper rim 126 of the outportion 112. The tips 124, as seen in FIG. 10, also pass throughrecesses or scallops 126 that are equally spaced about the upper rim 127of the inner portion 111. When the tips 124 of the handle 123 are fullyinserted (as shown in FIG. 10) relative rotation between the inner andouter portions 111, 112 is prevented. In preferred embodiments, thehandle 123 comprises a bail 130 located between the two tips 124. Thebail conforms to the shape of a circumferential shoulder 131 toward theupper margin of the outer portion 112. The bail 130 has a reflex portion135 that is received, when the bail is in its lower most or restingposition, in one or the other of a pair of receiving recesses 136 formedon an upper periphery of the outer portion 112.

As shown in FIG. 12, an espresso coffee making machine 150 may have twointernal boilers, one for steam 151 and one for hot water 152. Steamproduced by the steam boiler exits via a port 153 and is discharged bythe device's steam wand and the production of steamed beverages such asmilk foams that are used in the production of latte and cappuccino etc.The steam discharge from the port 153 is controlled by anelectromechanical or mechanical steam discharge valve 154. The valve iscontrolled by the device's micro processor control unit (MCU) 155. TheMCU 155 also controls the electromechanical water discharge valve 156 ofthe hot water or coffee boiler 152. A user interface 157 providesvarious switches, knobs, controllers, selectors or other input devicesrequired for the user to control the operation of the espresso machine150 by providing inputs and values to the MCU 155. User preferences,values, machine states, options and process parameters etc. may bedisplayed to the user via a graphic interface or display 158 that isdriven or controlled by the MCU 155. A reservoir or water tank 159supplies water to a pump 160 that supplies water to the steam boiler151, the pump 160 being controlled by the MCU 155. A separate pump 161pumps water from the water tank 159 into the coffee boiler 152. Thecoffee boiler's supply pump 161 is controlled by the MCU 155. Thereservoir 159 may have a level sensing device 162 that provideinformation to the MCU 155 regarding the volume of water in the tank159. In some embodiments, the tank is removable by the user forrefilling.

In this example, both boilers 151, 152 are provided with a drain opening163, 164 located at or closely adjacent to the lowest point within eachboiler. The output of the drains 163, 164 are controlled by drain valves165, 166. The drain valves 165, 166 may be electromechanical and therebycontrolled by the MCU in response to a user input (or otherwise) or maybe mechanical valves that are directly operated by the user. The purposeof the user operated valves 165, 166 is to allow the boilers to bedrained completely during the scaling operations.

In preferred embodiments, the water tank 159 incorporates a userreplaceable resin type filter 167. The MCU 155 provides the user withprompts at calculated intervals for both replacing the filter 167 andconducting descaling operations relating to one or both boilers 151,152, independently or simultaneously.

A user uses the interface 157 to initiate a de-scale sequence. The userfirst empties the water tank 159 and when there is a filter, optionallyand temporarily removes the water filter 167 from the tank 159. The tankis then replaced after having been filled with a de-scale solution of akind well known in the art. The coffee machine's drip tray is removed,emptied and reinstalled. After this, the drain valves 165, 166 areeither opened by the user or, if electromechanical valves are used, bythe MCU 155. Water will then flow from the tanks into the coffeemachine's drip tray. The valves 165, 166 are closed when water stopsflowing into the drip tray or wherever the drained water is otherwisedischarged. After both valves are closed, the user makes a selection onthe interface 157 that causes the MCU 155 to proceed to the next step.The outputs of the steam boiler's level sensors 170 and the waterboiler's level sensors 171 (or other means) are read by the MCU 155 todetermine whether or not the boilers are empty. If one or both boilersare not empty, the machine will provide the user with a visual oraudible warning indicating that the emptying process must be repeated orcompleted. When the boilers are actually empty, the MCU 155 will causethe supply pumps 160, 161 to fill each boiler. The boiler temperaturemay be adjusted to an optimum level for de-scaling. The MCU 155 willthen initiate a countdown of a de-scale interval, in this example, about20 minutes. When the boilers are filled with de-scale solution, thecountdown timer will start and the countdown will be visually indicatedor displayed on the machines graphic display 158. After the de-scaleinterval, the MCU 155 will show a countdown time of “zero” or otherwiseprompt the user to open the drain valves 165, 166. If the drain valvesare electromechanical, the MCU 155 may cause them to open without userintervention.

The valves 165, 166 are then closed after water stops flowing into thedrip tray, whereupon the user enters another command via the interface157 so that the MCU 155 can proceed to the next step. This will causethe MCU to fill the boilers with fresh water from the reservoir andinitiate a new, preferably shorter, countdown. Any de-scale solutionremaining in the boilers will dissolve into the fresh water. After acountdown of, say, five minutes, the user will be prompted to open thedrain valves 165, 166. The MCU will perform this operation whenelectromechanical valves are used. The rinse cycle may be repeated, ifrequired. After rinsing, the valves 165, 166 are closed and normalbrewing operations can be re-commenced.

As suggested by FIGS. 13 and 14, one or both boilers 151, 152 areprovided with drain openings or ports 163, 164 that are located at alowermost point of the interior of the boiler. The drain ports 163, 164are connected to the drain valves 165, 166 by flexible or other tubes170, 171 to the respective valves 165, 166. As illustrated, the drainvalves 165, 166 discharge into the coffee machine's removable drip tray172. As previously mentioned, the drain valves 165, 166 may beelectromechanical or manually operable by the user. In this example,each drain valve 165, 166 has a threaded or rotating valve actuator orgate 173, 174 that is easily accessible by the user and preferablylocated on one of the front surfaces of the coffee machine 150. Aprotective or decorative cap 175 may be used to protect or cover theuser accessible actuators 173, 174.

In particularly preferred embodiments, the device's MCU 155 calculates arecommended de-scale interval and provide the user with a visual prompt(on the display 158) regarding when a de-scale operation should beconducted. It is preferred that the de-scale interval be calculated withreference to the user's actual water hardness. Accordingly, the user maybe supplied with water hardness test strips. In one example, the teststrips provide five distinct levels or indications of water hardnessusing the test strips and the reading providing by them, the user entersan integer between 1 and 5 to the MCU 155 via the interface 158. In thisexample, the five levels of water hardness correspond to (from lowest tohighest, 1-5) are: below 50 ppm CaCo₃, 50-120 ppm CaCo₃, 120-240 ppmCaCo₃, 240-360 ppm CaCo₃ and above 360 ppm CaCo₃.) A counter in the MCUkeeps track of the number of operations performed by each boiler or thevolume of water handled by each boiler when in use. The MCU can displayan indication, such as an incremental numerical value on the display 158separately, for replacement of the resin filter 167 and for when ade-scale operation is required in respect of either the steam boiler 151or the coffee boiler 152, or both of them. In preferred embodiments, theMCU may establish a lower limit, being a minimum number of operations orvolume of water processed before providing a prompt to the userregarding the need to perform a de-scale operation. In some embodiments1500 coffee cycles need to be recorded by the MCU prior to the issuanceof a graphic user prompt regarding de-scale.

A graphic user prompt generated by the MCU regarding de-scale can alsobe made on the basis of the degradation in performance of the electronicwater level detectors 170, 171 in one or both boilers 151, 152. Thebuild-up of scale on the probes of the level detectors 151, 152 resultsin increased resistance on the probes. The higher resistance results ina reduction in their performance and is recorded or detected by the MCUas a reduction in the voltage output reading that is otherwise used todetect the presence of water in the boiler. In this example, no voltageis recorded across the probes or pins of a water level indicator when atank is empty and 1.9 volts is recorded when water is in contact with apair of pins or probes in a water level indicator 170, 171. When thenominal indicated voltage drops from 1.9 volts to 1. 7 volts, the MCUinterprets this as sufficient degradation to provide the user with ade-scale prompt on the display 158, so long as other conditions such asthe minimum volume or number of coffee cycles has been satisfied. Timelyde-scaling operations will prevent the boilers and the probes associatedwith the water level indicators 170, 171 from failing.

In one example, the MCU 155 measures and records the volume of waterhandled by a boiler and uses this record of water volume as anadditional way of prompting the user to perform a de-scaling operation.The generation of the user prompt for de-scaling may also take intoaccount the state of the water tank's filter 167. For example, the MCUcounter and any graphic display of it, can be changed or incremented,from an initial level, at two different rates, one being for when thefilter is within its useful life, and a second higher rate after thenominal filter life has expired. In respect of the de-scale operation, anominal counter upper limit may be established as an auditory value of600. This value may be displayed to the user. The initial value isincremented (from zero) by a value of 3 for each 200 litres of waterprocessed by the boiler. After the expiry of the nominal filter life,this same volume of 200 litres represents an increment in the counter by6. The table below provides the increment applied by the MCU anddisplayed to the user for both the resin filter replacement and thede-scaling operations. The table is based on a nominal count-up from avalue of 600 for the de-scale operation and a nominal value of 300 forthe prompt for the water tank resin filter change. The exemplary watervolume associated with each increment and the amount of the incrementare shown in the table for both the filter change and the de-scale, foreach of the five aforementioned water hardness levels.

De-Scale Change Filter Counter/L Water Volume Counter Volume WithinFilter After Filter Hardness (L) (per L) (L) Life (per L) Life (per L) 1100 3 200 3 6 2 75 4 150 4 8 3 50 6 100 6 12 4 30 10 75 8 16 5 10 30 5012 24

As shown in FIGS. 14-20, an espresso coffee making machine mayincorporate an integral coffee grinder 180 with hopper 181, 182 andtamping augur for filling a portafilter 200 engaged with a fill head201. The fill head 201 receives ground coffee from the grinder anddischarges it into the portafilter. The fill head 201 also contains andorients the rotating tamping augur. The operation of both the grinderand augur can be controlled simply by manipulating the portafilter 200that is in engagement with the fill head 201.

As suggested by FIG. 15, the portafilter 200 has three main orientationswith respect to the fill head 201. In the “insert” position 202 theportafilter 200 has just been fully elevated into position with theunderside of the fill head 202 but has not been rotated relative to thefill head 201. As will be explained, the fill head 201 has a femalebayonet assembly, being features 210 that cooperates with male bayonetfeatures 228 normally associated with the portafilter 200. In the insertposition, the female bayonet features receive the male features prior torotation of the portafilter 200. In a “home” position 203 an initial orpartial rotation of the portafilter 200 defeats a safety interlock, thusallowing for power to be supplied to the motors that operate both thecoffee grinder and the tamping augur. In the home position 203, neitherthe coffee grinder's motor nor the tamping augur's motor are actuallyactivated. In order to activate the grinder and augur motors, theportafilter 200 is rotated into a start/stop position 204. Both motorswill be suitably controlled by the MCU 155 so long as the portafilter200 is in the start/stop position 204. In preferred embodiments, thefemale bayonet features 210 are biased so as to return the portafilter200 to the home position if the portafilter's handle 205 is released.The portafilter 200 can only be inserted and removed when it is in theinsert position 202.

As shown in FIG. 16, the female bayonet features 210 of the fill head201 include a pair of interconnected rings 211, 212. Each ring 211, 212includes a cam surface 213, 214. Each cam surface cooperates with anoptional cam follower 215, 216. Each cam follower is pivotally orotherwise attached to a micro switch 217, 218 or other electricalswitch. Accordingly, rotation of the portafilter 200 causes a rotationof the rings 211, 212. Rotation of the rings, 211, 212 brings the camsurfaces 213, 214 into and out of engagement with the cam followers 215,216. Thus, the two switches 217, 218 can be switched or activatedindependently in accordance with the position of the portafilter 202,203, 204. FIG. 16 illustrates the insert position 202 in which theportafilter is inserted, but not rotated relative to the fill head 201.Neither of the switches 217, 218 is activated.

FIG. 17 illustrates the home position 203. In this orientation, theportafilter 201 has been rotated so that the cam surface 213 of thelower ring 211 acts to actuate the lower micro switch 217, in thisexample through the intermediate action of the lower cam follower 216.This action activates the circuits that allow the MCU to potentiallycontrol the operation of the grinder motor and augur motor.

Further rotation of the portafilter 200 relative to the fill head 201causes the portafilter 200 to enter the start/stop position 204 as shownin FIG. 18. In this orientation, both cam surfaces 213, 214 havedisplaced both cam followers 215, 216 and both switches 217, 218 havebeen tripped or activated. When both switches 217, 217 are activated,the MCU is able to and does control the activity of the grinder motorand augur motor in accordance with a pre-established routine orinstructions and preferences provided by the user through the interface157.

As shown in FIG. 19, the lower ring 211 is received by the engagementcollar 220 of the fill head 201. The collar 220 is attached to a frontsurface of the coffee making machine. In preferred embodiments, thelower ring 211 is not free to rotate until the portafilter 200 isinserted and at least partially rotated. This is accomplished byproviding the lower ring 211 with a anti-rotation step 221 formed on thelower rim of the lower ring 211. In the rest position, the step 221engages with and cooperates with a second step 222 formed on the collar220. In order that the steps 221, 222 be disengaged, the portafilter 200is inserted into the collar 220 and partially rotated. A ramped undersurface 227 associated with the portafilter's male bayonet features 228causes the upper rim 229 of the portafilter to lift the lower ring 211against the biased imposed by the ball and spring elements 223. When thesteps 221, 222 are disengaged, the lower ring 211 can rotate relative tothe collar 220. The lower ring 211 is biased downwardly by, in thisexample, four ball and spring detent elements 223. Each of the balls 224cooperates with an arcuate track or groove 225 formed on an uppersurface of the lower rim 211. Each track or groove 225 has a centraldetent 226 that works in cooperation with the ball and spring elements223 to create haptic feedback and to assist in the maintenance of theportafilter 200 in the home position 203.

The lower ring 211 has two upright posts 230. The posts pass througharcuate through openings 231 formed on a collar 232 that acts as a mountfor the motorised augur assembly. The upper ring 212 is preferablyattached to the posts 230 of the lower ring 211 by fasteners 233. Thus,the upper and lower rings 211, 212 rotate in unison, the movement beinglimited by the ends of the slot 231. The sleeve 232 provides a journalor other bearing for receiving the rotating shaft 234 of the augur fanassembly 235.

As shown in FIG. 20, the bias mechanism that returns the portafilter tothe home position may comprise one or more (in this example two) tensionor return springs 240, 241. In this example, each of the return springsis affixed, at one end, to the upper ring 212 and at an opposite end, toa static portion such as a part of the collar 232. Thus the springs 240,241, curve to occupy the channel between the curved outer surface 242 ofthe upper ring 212 and the curved inner surface of the cover 243 of thefill head assembly 201. The springs 240, 241 are only elongatedsignificantly with the portafilter 200 is between the home position 203and the start/stop position 204.

As shown in FIG. 21, a motorised tamping augur 250 has an electric motor251 that drives a power train or gearing assembly 252 which in turndrives the shaft 253 to which the augur fan 254 is directly orindirectly affixed. In this example, the vertical location or verticalheight of the fan 254 is manually adjustable. The adjustment couplingand spacer 255 creates a threaded interconnection between the shaft 253and the fan 254 that can be adjusted by a user and then fixed in itsposition with a radial set screw 256. In this example, the lower end ofthe shaft 253 is threaded 257. The threads 257 cooperate with femalethreads 258 that are formed along the interior bore of a coupling hub259. The directionality of the threaded interconnection between theshaft and the hub 253, 259 is such that the threads are tightened as theaugur is used. The hub 286 has an intermediate collar 292 for limitingthe axial location of the fan 285. To prevent the hub 259 from advancingup the shaft and changing the vertical height of the fan 254, thecoupling 255 is provided with a spacer 260 that cooperates with the hub259. As shown in FIGS. 21 and 22 the spacer 260 has internal threads 261that cooperate with external threads 262 formed around an exterior ofthe hub 259. After the augur fan vertical height is established bythreading or unthreading the hub 259 relative to the shaft 253 (usingthe threaded inner connection 258, 257) the spacer 260 is advancedtoward the shaft 253. When the upper surface 263 of the spacer makescontact with a shoulder 264 located above the threads 257, the radialset screw 256 is tightened against the hub's external threads 262, thusimmobilising the coupling 255 relative to the shaft 253. The externalthreads 262 of the hub 259 may have flat areas 271 for better receivingthe radial set screw 256 and thus the inner connection between thespacer 260 and the hub 259. The spacer may be provided with a centralopening 265 for receiving a reduced diameter portion 266 of the shaft253. It will be appreciated that other forms of fan height adjustmentare contemplated using a variety of threaded, frictional or othermechanical means.

A lower part of the augur fan hub 259 has one or more flats or features265 and may be tapered to be inserted into and cooperate with a hubreceiving opening or socket 270 formed centrally in the augur fan 254.

An alternate form of augur fan is shown in FIGS. 23-26. In order tobetter distribute the coffee grinds within the portafilter, such anaugur fan wobbles or pivots about the vertical axis of the driving shaft253 at any given augur fan height. In order to do so, the coupling 259has, for example, a transverse through opening 281 that receives a pivotpin 282 that passes through one or more openings 283 in the area of thehub receiving socket 284 of the augur fan 285 thus creating a pivotinginterconnection. The pivoting motion of the augur fan 285 isaccommodated by a vertical slot 287 formed through a side wall of thehub receiving socket 284. A compression spring or other bias member 288is located within a radial opening 289 formed in the hub and exerts atilting force against the augur fan 285 as shown in FIGS. 24 and 25.When there is no load on the augur fan 285, the compression spring 288will place the augur fan in an off-axis or tilted orientation shown inFIG. 25. When the level of coffee grinds rises within the portafilter,the grind will overcome the effect of the spring 288 and restore theaugur fan to the horizontal or perpendicular condition shown in FIG. 24.Thus, the tamping and polishing process will be completed with the fanin a stable perpendicular orientation relative to the shaft 253. Theamount of tilt or wobble of the fan 285 relative to the shaft 253 can belimited or adjustably limited by an abutment or vertical adjustmentfeature or screw 290. In this example, the tilt limiting screw 290 isreceived within a threaded opening 291 in the augur fan, adjacent to thecentral opening 292 that receives the hub 259. As shown in FIG. 25, thetop of the adjustment screw 290 abuts the hub to establish a maximumextent of tilt or wobble. The wobble limiting feature 290 may be fixed,integral with the fan 285 or adjustable in the manner depicted in FIGS.24 and 25.

As shown in FIG. 26, the female hub receiving portion 300 of the fan 285may optionally include a vertical slot 287, 301 in the area of the tiltlimited feature 290 so that the limiting feature or adjustment screw 290can be accessed with the appropriate tool or driver, as required.

FIG. 27 illustrates an espresso coffee machine 310 in schematic form. Adevice 310 of this type has the capability of operating the tampingaugur, in different modes, to achieve optimal filling and compaction ofthe coffee within the portafilter. The coffee machine 310 comprises abean hopper 311 for containing and dispensing beans into a grinder 312having a grind adjustment mechanism 313 with, for example, an adjustablelower grinder burr, as is known in the art. The grinder is driven by anelectric grinder motor 314 having, for example, a clutch engagement 315with the grinder 312. Ground coffee is dispensed 316 above the tamperaugur's and fan. The augur is driven by a DC augur motor 318. Anoptional torque sensing tamp detector 319 may be interposed between thetamping augur 317 and the augur motor 318. The device's main control PCB(or MCU) 320 receives inputs from a hopper interlock sensor 321, thegrind adjust position sensor 322, the grinder motor's thermostat,overheat detection sensor and motor speed sensor 323, 324 and 325. ThePCB 320 also receives appropriate signals from the portafilter safetyinterlock sensor 326 the optional tamp detector torque sensor 327, theaugur motor speed sensor 328 and other sensors and feedback devices asrequired. It will be appreciated that the aforementioned array ofsensors may be deployed or not in accordance with the sophistication,complexity, cost and design parameters of the subject coffee machine310. The PCB 320 also has a capacity to receive inputs and control themachine's user interface 330, its main graphic display 331, the power tothe augur motor 332, the activation switch to the tamper augur 333, thepower supplied to the grinder motor 314 and other controllable deviceswithin the machine as required.

In order to better distribute coffee grounds within the portafilter,using the motorised tamper augur and augur fan suggested by FIG. 27 andas otherwise known in the art, a sequence of events or method 340 ispracticed in accordance with FIG. 28. In the example of FIG. 28, uniformdistribution of grounds is achieved by first using the PCB 320 toactivate a grind and tamp cycle that involves rotation of the augur fanwith the augur motor 318. The motorised tamp mechanism is activated, forexample, four seconds and the PCB 320 receives feedback during thisactivation 341 to indicate whether or not the portafilter has beencompletely filled. The feedback to the PCB 320 can be either from thetamper torque sensor 327, or for example, by monitoring the load on theaugur motor 318 using the power draw on the motor as an indication ofthe work performed by the motor, as will be explained. On the basis ofthe feedback received by the PCB 320 the PCB 320 makes a determinationof whether or not the portafilter is filled 342. If the PCB 320determines that the portafilter is filled then the grinder and tamperare deactivated and an indication is provided to the user that the cycleis completed and that the portafilter is full 343. If the PCB 320determines that the portafilter is not filled, the coffee grinder 312 isactivated and the tamping mechanism is rotated in a first direction, forexample, clockwise, for a short duration, for example, 1.5 seconds 344.Subsequently, the grinder is either activated or maintained inactivation and the tamper is operated at a slower speed for a shortduration, say for example, one half second 345. After the tamper isslowed or stopped 345, the grinder is either activated or continues toactivate as the tamper is activated in an opposite direction, sayclockwise, for a second interval 346. The second interval may be thesame as the first interval 344, say 1.5 seconds. After this, the grinderis stopped and the tamper is rotated in the first direction (e.g.clockwise) for an interval of, for example, about 4 seconds for thepurpose of providing a flat surface on the dose in the portafilter, ifthe portafilter is full 347. This is referred to as a polishing step. Atthe end of the polishing step 347, the PCB 320 makes a determination asto whether or not the portafilter is full 348. This may be done in thesame manner as the earlier coffee detection step 342. If the portafilteris not full, the grinder and tamper are activated again, in the firstdirection 344. The cycle is then repeated 345, 346, 347, 348 until thePCB 320 determines that the portafilter is full. If it is, the grinderand tamper are deactivated and an indication is provided to the userthat the portafilter filling cycle is complete 343.

As previously mentioned, as an alternative to a tamper torque sensor 327or a tamper height detection mechanism, the PCB 320 can use the augurmotor's load or current draw to determine whether or not the portafilteris full and the surface has been polished. A tamper motor current sensor(335 in FIG. 27) cooperates with the augur motor 318 and provides loadindicative signals to the PCB 320. The grind and tamp cycle is thusfirst activated by a user 360. The mechanism is run for, for example,four seconds and during this time, an indication (audible or visual orboth) may be given to the user that the grinder and tamper status isactive 361. When no coffee grinds are in contact with the augur fan, thetamper motor 318 draws the least current and is under the lowest load.As the ground coffee level within the portafilter rises, contact iseventually made within the augur fan. At this point, the motor loadincreases. The PCB 320 compares the motor load from the sensor, e.g. 335to a pre-established polish threshold value 362. The polish threshold isa load or current level of the augur's motor that indicates that theportafilter is full. If the polish threshold has not been met the coffeegrinder 312 is activated and a grinder timer is started 363. The tampermechanism either remains activated or is activated as the grinderoperates 363. The PCB 320 again compares the motor current or load to apre-established threshold value 364. If the motor current has notincreased to the threshold value, the PCB 320 compares the duration ofthe current detection step 364 to a pre-established time value, forexample, 60 seconds 365. If the duration of the current detection step364 has not exceeded the threshold time value 365 the grinder and tampercontinue to operate 366 until either the current threshold has beenreached 364 or the threshold time 365 has been exceeded. If either ofthese conditions are met, the grinder is stopped while the tampermechanism operates 366. Concurrently, a tamp timer associated with thePCB 320 is activated. The PCB 320 then compares the motor current ordraw to the polish threshold 367. Where the current has exceeded thethreshold the grinder and the tamper are both deactivated and anindication is provided to the user that the grinding and tamping cycleis completed 368. If the current is lower than the polish threshold thePCB determines whether or not the tamp timer has exceeded apre-established value such as four seconds 369. If the pre-establishedtime has been exceeded, the grinder and tamper are deactivated anoptional indication is provided to the user that the grind and tampcycle is completed 368. If the PCB determines that the polish time hasnot yet elapsed, the current comparison and timer comparison steps 367,369 are repeated 370 until such time as the polish threshold is exceededor the tamp timer has exceeded the pre-established duration whereuponthe grinder and tamper are deactivated and an indication is provided tothe user that the cycle is complete 368. It will be appreciated that afine tuning of the system described in FIG. 29 may require a timeconstant to be added to current detection step 362, 367 in order thateither the coffee grinder or the tamper operate for a pre-establishedtime interval after a current threshold has been reached. It will alsobe appreciated that the method and apparatus relating to the detectionof a full and polished portafilter disclosed with reference to FIG. 29may be combined with the method and apparatus of coffee grindsdistribution disclosed in FIG. 28.

Although the technology has been described with reference to specificexamples, it will be appreciated by those skilled in the art that thetechnology may be embodied in many other forms.

As used herein, unless otherwise specified the use of the ordinaladjectives “first”, “second”, “third”, etc., to describe a commonobject, merely indicate that different instances of like objects arebeing referred to, and are not intended to imply that the objects sodescribed must be in a given sequence, either temporally, spatially, inranking, or in any other manner.

Reference throughout this specification to “one embodiment” or “anembodiment” or “example” means that a particular feature, structure orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the present technology. Thus, appearancesof the phrases “in one embodiment” or “in an example” in various placesthroughout this specification are not necessarily all referring to thesame embodiment or example, but may. Furthermore, the particularfeatures, structures or characteristics may be combined in any suitablemanner, as would be apparent to one of ordinary skill in the art fromthis disclosure, in one or more embodiments.

Similarly it should be appreciated that in the above description ofexemplary embodiments of the technology, various features of thetechnology are sometimes grouped together in a single embodiment,figure, or description thereof for the purpose of streamlining thedisclosure and aiding in the understanding of one or more of the variousinventive aspects. This method of disclosure, however, is not to beinterpreted as reflecting an intention that the claimed technologyrequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Any claimsfollowing the Detailed Description are hereby expressly incorporatedinto this Detailed Description, with each claim standing on its own as aseparate embodiment of this technology.

Unless specifically stated otherwise, as apparent from the followingdiscussions, it is appreciated that throughout the specificationdiscussions utilizing terms such as “processing,” “computing,”“calculating,” “determining” or the like, refer to the action and/orprocesses of a microprocessor, controller computer or computing system,or similar electronic computing device, that manipulates and/ortransforms data.

Furthermore, while some embodiments described herein include some butnot other features included in other embodiments, combinations offeatures of different embodiments are meant to be within the scope ofthe technology, and form different embodiments, as would be understoodby those in the art. For example, in the following claims, any of theclaimed embodiments can be used in any combination.

Thus, while there has been described what are believed to be thepreferred embodiments of the technology, those skilled in the art willrecognize that other and further modifications may be made theretowithout departing from the spirit of the technology, and it is intendedto claim all such changes and modifications as fall within the scope ofthe technology.

While the present technology has been disclosed with reference toparticular details of construction, these should be understood as havingbeen provided by way of example and not as limitations to the scope orspirit of the technology.

1. An augur fan for a coffee compaction augur, the augur fan including:a hub; one or more tamping blades extending from the hub; a passagebetween the one or more tamping blades allowing coffee grounds to fallbetween the one or more tamping blades; and a wiper carried by at leastone of the one or more tamping blades, the wiper being adapted to reducea gap between an outer periphery of the respective one or more tampingblades and an inside wall of a filter basket when the augur fan isoperated within the filter basket.
 2. The augur fan of claim 1, whereinthe augur fan includes two blades.
 3. The augur fan of claim 2, whereineach blade is semi-circular in plan view.
 4. The augur fan of claim 1,wherein each of the one or more tamping blades has a helicalconfiguration such that each blade has a leading edge higher inelevation than a trailing edge, such that, when the augur fan isoperated within a filter basket containing coffee grounds, the trailingedge acts to compress the grounds below the fan.
 5. The augur fan ofclaim 1, wherein the augur fan is manufactured from a rigid polymer or ametal and the wiper is elastomeric.
 6. The augur fan of claim 1, whereinthe wiper includes a wiper insert and the augur fan includes a recess ona rim or outer edge of at least one of the one or more blades, therecess being adapted to receive the wiper insert.
 7. The augur fan ofclaim 6, wherein the wiper insert is replaceable.
 8. The augur fan ofclaim 6, wherein the wiper insert comprises a body having, at one end,an enlarged head, and at another end a vertically aligned rib, lip, orbead, wherein the rib, lip or bead projects beyond the outer peripheryand extends so as to, when the augur fan is operated within the filterbasket, sweep or contact the inner wall of the filter basket.
 9. Theaugur fan of claim 8, wherein the recess comprises a terminal pocket forreceiving the enlarged head of the wiper insert.
 10. The augur fan ofclaim 6, wherein the wiper insert comprises a body having parallel sidesand a thickness of the wiper insert is approximately the same as athickness of the tamping blade carrying the wiper insert in the areasurrounding the recess.
 11. The augur fan of claim 10, wherein therecess has parallel sides for snugly receiving the parallel sides of thebody of the wiper insert.
 12. The augur fan of claim 6, wherein therecess has an internal rib that cooperates with a corresponding slot inthe wiper insert to frictionally retain the wiper insert within therecess.
 13. The augur fan of claim 1, wherein each blade carries awiper.
 14. A motorised tamping or compaction augur having the augur fanof claim 1.